By then around 91 of your 120 monthly payments will have been made. The capital would have been paid off a little slower at first as most of your fixed payment would have been interest payments but as the capital was gradually repaid the interest payment gradually fell and the speed at which capital was paid off increased.
I reckon around £9000 will be outstanding by July 2015. I used this
http://dev.trigoldcry.../mortgage-calculators
I could do a more accurate calculation if I had time but the answer wouldn't vary by more than a thousand pounds either way